1. Field of the Invention
The present invention relates to the field of gaming, particularly machine based gaming such as slot machines and video gaming machines, and more particularly to gaming machines having bonus events.
2. Background of the Art
Gaming devices typically include an array of mechanical elements on which wagers can be placed. The most common gaming device is the slot machine. This is a device that allows wagers to be entered in a mechanical or electromechanical machine, and the machine generates a random or pseudo-random outcome producing, for example, sets of symbols. These sets of symbols are usually displayed in columns and rows. Predetermined sets or collections or sequences of the symbols within the columns or rows are defined as winning outcomes, and other sets are therefore losing outcomes. Originally slot machines were mechanical devices employing 3 physical reels with various symbols displayed on the reels. After placing a wager, the reels were put into motion and randomly stopped. Wagers were paid depending upon the outcome of the types and positions of symbols.
Gaming machines, such as the standard slot machines have evolved, particularly with the advent of computer technology, which has enabled far greater variety in game play and additional features. Most present day machines are processor driven and have video display monitors. The processor based systems allow for not only a better visual appearance, but significant variation in the underlying games, the ordering of play lines, side bet games, bonus games, and complex wagers and games that are automatically processed. Rather than the earliest three-reel slot machines with a single pay line, a single machine may play one hundred (100) or more games at a single time, and even have multiple games with 10, 20 30 or more separate pay lines.
Typical random frame symbol video slots have, for example, three rows and five columns of available frames within which symbols are randomly provided. The pay lines may be horizontal, vertical, diagonal or non-liner (e.g., zig-zag) and random symbols of special types may be used for what is known as a scatter pay, where the appearance of a certain number of symbols anywhere on the screen is determined to be a winning event.
Second screen, top box, bonus and other special features have become desirable to add variety and the potential for larger awards to the game. The addition of progressive jackpots, in which a portion of a wager from one or more machines builds up in a pot or jackpot, and that jackpot is awarded on an infrequent event, have also become popular. The use of the computer, processor, interconnectivity and video displays have greatly advanced the use of such systems.
Lower denomination games (e.g., $0.01 unit wagers, $0.05 unit wagers) have become very popular. By providing large numbers of pay lines and large numbers (e.g., up to 100× units per pay line), significant revenue can still be generated from small denomination unit wagers.
Although the term reel mapping refers to the distribution and proportions and frequency of images on physical reels, electronic systems perform a similar function to provide random outcomes from the virtual or video reels. This can be done by random number generators, which can be weighted to vary the probabilistic frequency of individual symbols. For example, if there are twelve different symbols that can theoretically be possible on a single column (a single virtual reel), the random number generator may have 1000 available numbers that are randomly selected. Symbol 1 may have 250 out of the 1000 numbers, and therefore have a probability of occurrence of 250/1000. That symbol would likely be a low value or likely losing symbol or a blank space. Symbol 2 might have 150 numbers assigned to that symbol, so that it would appear 150/1000 spins. That symbol would also likely have a low potential value in gaming outcomes, such as a lemon in traditional slot symbol events. Symbol 3 also might have 150 numbers assigned to that symbol, so that it would appear 150/1000 spins. That symbol would also likely have a low potential value in gaming outcomes, such as a plum in traditional slot symbol events. This distribution has already used up more than half of the available numbers from the random number generator (550/1000). More valuable or potentially valuable symbols will have fewer numbers assigned to them, so that the random number generator will select those more valuable symbols less frequently on a long term event basis. Each reel may be separately weighted. For example, a maximum jackpot symbol that requires five matching symbols in a horizontal row may be weighted so that there are 4/1000 numbers assigned in the first column, 3/1000 numbers in the second column 8/1000 numbers in the third column, 20/1000 in the fourth column, and 1/1000 in the fifth column. If the same numbers were assigned to each symbol in each column, there would be less control over the frequency of the final output.
The term “reel” as traditionally referencing a physical reel in a slot machine, is still a convenient term to reference event outcomes, whether the reel event outcomes being referred to are individual frame outcomes (e.g., a single symbol), individual column outcomes (e.g., the locus of frames that would normally appear on a single physical reel) o, column outcomes (where adjacent reel symbols are sequential and horizontal or game outcomes where all available symbol-holding positions have symbols or blank spaces assigned to them.
Bonus events may take many different forms. The bonus events may be triggered or randomly occur. Bonuses may be separate games, increased awards on games similar to the underlying game being played, selection games (e.g., pick and reveal), or random event outcomes run by the processor.
Published U.S. Patent Application Document No. 20070026924 (which claims priority from U.S. Provisional Application Ser. No. 60/702,305 filed on Jul. 23, 2005) describes a gaming device comprising: at least one symbol display that includes at least one award symbols, said award symbol associated with at least one award; a plurality of prize indicators, wherein each has an associated number of awards needed to access said prize indicator, and each of said prize indicators includes at least one prize; a processor operable with said symbol display to generate the award symbols and to enable the player to selectively access at least one prize. Many different variations and alternatives are described therein relating to bonus games.
Published U.S. Patent Application Document No. 20120064961 (Ventura) shows a video and physical gaming system in which a method of playing a game and a gaming device is configured to present a game, a plurality of reels display a base set of symbols. The symbols are used to define a base game outcome. In the event a nudge feature is triggered, such as by receipt of trigger symbols in the base game, reels having associated trigger symbols are locked and individual ones of the reels are nudged to new positions, wherein after a particular reel has been nudged, a new game outcome is evaluated. The reels may be nudged sequentially. Other triggers, such as receipt of additional numbers of trigger symbols, may also trigger a primary bonus game, which bonus game may further trigger one or more secondary bonus games.
Published U.S. Patent Application Document No. 201000203964 (Berman) describes a system and method for allowing gaming device participants to effect trades of player assets for improved odds of attaining gaming bonus events. A player engages in play of a gaming activity, such as a slot game, which includes a standard mode of play and a bonus mode of play. Player assets are traded for an increased probability of attaining a bonus event associated with the bonus mode. A trade amount is surrendered by the player as part of the trade, and the probability of the player attaining the bonus event increased, thereby allowing the player to engage in bonus activity sooner, more frequently, or when otherwise less available to the player. U.S. Pat. No. 5,344,144 (Canon) describes an accumulator for a multiple jackpot gaming system wherein the accumulator has the facility for date stamping jackpot-wins, recording the identification of devices and changes being made by such devices to its data and/or programming, allocating coins-in to one or more jackpot groups and/or to one or more increment rates assigned to a particular jackpot group, operate its jackpot stack so as to clear stack positions immediately upon clearing a jackpot, and control jackpot handling from its main programming loop.
All references cited herein are incorporated by reference in their entirety.